https://doi.org/10.5194/ms-9-147-2018
<b>Structural integrity investigation for RPV with various cooling water levels under pressurized melting pool</b><br>
Jianfeng Mao, Yunkai Liu, Shiyi Bao, Lijia Luo, Zhiming Lu, and Zengliang Gao<br>
Mech. Sci., 9, 147-160, https://doi.org/10.5194/ms-9-147-2018, 2018<br>
The traditional concepts on severe accident mitigation weren't seriously challenged until the occurrence of Fukushima accident on 2011, suggesting the structural behavior had not been appropriately assessed. Therefore, the paper tries to address the structure-related issue on determining whether structural safety can be maintained or not with the effect of various water levels and internal pressures created from core meltdown accident. The creep and plastic damages are interacted with each other
2018-03-02T11:30:26+01:00https://doi.org/10.5194/ms-9-103-2018
<b>Module-based structure design of wheeled mobile robot</b><br>
Zirong Luo, Jianzhong Shang, Guowu Wei, and Lei Ren<br>
Mech. Sci., 9, 103-121, https://doi.org/10.5194/ms-9-103-2018, 2018<br>
A systematic method was proposed for the synthesis and creative design of novel structures that can be used to build wheeled mobile robot. The proposed method has led to 236 new design schemes. Mathematical models and a software platform were developed to provide appropriate and intuitive tools for simulating and evaluating performance of the wheeled robots. Physical prototypes of sample wheeled robots were developed and tested, proving and validating the principle and methodology presented.
2018-02-27T11:30:26+01:00https://doi.org/10.5194/ms-9-123-2018
<b>Tool selection method based on transfer learning for CNC machines</b><br>
Jingtao Zhou, Han Zhao, Mingwei Wang, and Bingbo Shi<br>
Mech. Sci., 9, 123-146, https://doi.org/10.5194/ms-9-123-2018, 2018<br>
Due to the time-consuming and inefficient traditional tool selection method based on the human experience, we apply transfer learning to CNC tool selection issue in the field of industrial manufacturing. A unified expression of expert experience and process case is given in a more complex environment and then we improve the algorithm. The results show that the method we proposed can facilitate tool selection.
2018-02-27T11:30:26+01:00https://doi.org/10.5194/ms-9-91-2018
<b>Mechanical behaviour of a creased thin strip</b><br>
Jie Liu, Shanqing Xu, Guilin Wen, and Yi Min Xie<br>
Mech. Sci., 9, 91-102, https://doi.org/10.5194/ms-9-91-2018, 2018<br>
The mechanical behaviour of a creased thin strip under opposite-sense bending was investigated，revealing that a simple crease could significantly alter the overall mechanical behaviour of a thin strip. The influence of the geometrical parameters on the mechanical behaviour of the creased strip was studied. The deformation patterns of the thin strips from the finite element simulations were verified by physical models made from thin metal strips.
2018-02-20T11:30:26+01:00https://doi.org/10.5194/ms-9-81-2018
<b>Modelling, simulation and experiment of the spherical flexible joint stiffness</b><br>
Songyu Li, Liquan Wang, Shaoming Yao, Peng Jia, Feihong Yun, Wenxue Jin, and Dong Lv<br>
Mech. Sci., 9, 81-89, https://doi.org/10.5194/ms-9-81-2018, 2018<br>
The spherical flexible joint is used to connect the Tension Leg Platform to the seabed. It can provide low shear stiffness while bearing high compression force. So the research on the stiffness of flexible joint is necessary. The linear rotational stiffness of the flexible joint is formulated and FEM is used to verify the analytical solution. The increase of Poisson's ratio of the rubber layers will enhance the vertical compression stiffness but barely have effect on the rotational stiffness.
2018-02-19T11:30:26+01:00https://doi.org/10.5194/ms-9-71-2018
<b>Determining the range of allowable axial force for the third-order Beam Constraint Model</b><br>
Fulei Ma, Guimin Chen, and Guangbo Hao<br>
Mech. Sci., 9, 71-79, https://doi.org/10.5194/ms-9-71-2018, 2018<br>
The Beam Constraint Model (BCM) may yield large predicting errors (>&thinsp;5&thinsp;%) when the applied axial force goes beyond a certain boundary. We mathematically determine the nondimensional boundary of the axial force by the conditions of the positive definite quadratic form of the strain energy expression and the buckling load expressions. If the axial force is beyond the boundary, the Chained Beam Constraint Model (CBCM) can be used instead.
2018-02-16T11:30:26+01:00https://doi.org/10.5194/ms-9-61-2018
<b>Heat transfer and MHD flow of non-newtonian Maxwell fluid through a parallel plate channel: analytical and numerical solution</b><br>
Alireza Rahbari, Morteza Abbasi, Iman Rahimipetroudi, Bengt Sundén, Davood Domiri Ganji, and Mehdi Gholami<br>
Mech. Sci., 9, 61-70, https://doi.org/10.5194/ms-9-61-2018, 2018<br>
Analytical and numerical analyses have been performed to study the problem of magneto-hydrodynamic (MHD) flow and heat transfer of an upper-convected Maxwell fluid in a parallel plate channel. The Homotopy Analysis Method (HAM), Homotopy Perturbation Method (HPM) and fourth-order Runge-Kutta numerical method (NUM) are used to solve this problem. Also, velocity and temperature fields have been computed and shown graphically for various values of the important physical parameters.
2018-02-14T11:30:26+01:00https://doi.org/10.5194/ms-9-51-2018
<b>Design and evaluation of a continuum robot with extendable balloons</b><br>
Efe Yamac Yarbasi and Evren Samur<br>
Mech. Sci., 9, 51-60, https://doi.org/10.5194/ms-9-51-2018, 2018<br>
This article presents a novel continuum robot actuated by two extendable balloons. As inflated, the balloons apply a force on the wall of the tip, pushing the robot forward. The contribution of this study is the introduction of a novel actuation mechanism for soft robots to have extreme elongation (2000&thinsp;%) in order to be navigated in substantially long and narrow environments.
2018-02-07T11:30:26+01:00https://doi.org/10.5194/ms-9-41-2018
<b>A self-adjusting stiffness center design for large stroke compliant XY nanomanipulators</b><br>
Zhiqing Liu, Zhen Zhang, and Peng Yan<br>
Mech. Sci., 9, 41-50, https://doi.org/10.5194/ms-9-41-2018, 2018<br>
It is proposed a novel design method for large stroke XY compliant mechanisms. An important feature of the design lies in it restricts the parasitic rotation by reducing the moment of force instead of increasing the rotational stiffness widely utilized in the literature. It is presented a millimeter stroke XY nanomanipulator with the proposed design based redundant constraint in a case study. The proposed design provides an alternative to reduce the parasitic rotation of XY compliant mechanism.
2018-01-31T11:30:26+01:00https://doi.org/10.5194/ms-9-25-2018
<b>Pa<sup>2</sup> kinematic bond in translational parallel manipulators</b><br>
Alfonso Hernández, Erik Macho, Mónica Urízar, Víctor Petuya, and Zhen Zhang<br>
Mech. Sci., 9, 25-39, https://doi.org/10.5194/ms-9-25-2018, 2018<br>
In this paper the potentiality of using Pa<sup>2</sup> joints for designing robots with parallel structure and translational motion is studied. As the equations governing its motion are simpler than those of other structures, the control system of the robot is more efficient and reliable. The structure proposed has high stiffness improving the accuracy of its movements.
2018-01-22T11:30:26+01:00https://doi.org/10.5194/ms-9-15-2018
<b>A novel non-contact measuring system for the thread profile of a ball screw</b><br>
Leilei Zhao, Hutian Feng, and Qianfeng Rong<br>
Mech. Sci., 9, 15-24, https://doi.org/10.5194/ms-9-15-2018, 2018<br>
An automatic, non-contact measuring system for the thread profile of a ball screw was developed. It is capable of measuring most common features of the ball screw thread profile and can measure ball screws of different sizes and lengths. The accuracy of the measuring system was verified by comparing the image from the system with the image from the reference instrument and then, different ball screws were compared and evaluated, which was the main purpose of designing such a measuring system.
2018-01-09T11:30:26+01:00https://doi.org/10.5194/ms-9-1-2018
<b>Continuous Static Gait with Twisting Trunk of a Metamorphic Quadruped Robot</b><br>
Chunsong Zhang and Jian S. Dai<br>
Mech. Sci., 9, 1-14, https://doi.org/10.5194/ms-9-1-2018, 2018<br>
A continuous static gait of a quadruped robot benefited from the twisting trunk performing the increased stride length is introduced. After that, the increased stride length relative to the trunk twisting will be analysed mathematically. Other points impacting the implementation of the increased stride length in the gait are investigated such as the upper limit of the stride length and the kinematic margin. The increased stride length in the gait will lead the increase of locomotion speed.
2018-01-04T11:30:26+01:00https://doi.org/10.5194/ms-8-385-2017
<b>Prediction of surface location error in milling considering the effects of uncertain factors</b><br>
Xianzhen Huang, Fangjun Jia, Yimin Zhang, and Jinhua Lian<br>
Mech. Sci., 8, 385-392, https://doi.org/10.5194/ms-8-385-2017, 2017<br>
Machining accuracy of a milled surface is influenced by process dynamics.
Surface location error (SLE) in milling determines final dimensional accuracy
of the finished surface. Therefore, it is critical to predict, control, and
minimize SLE. In traditional methods, the effects of uncertain factors are
usually ignored during prediction of SLE, and this would tend to generate
estimation errors. In order to solve this problem, this paper presents
methods for probabilistic analysis of SLE in milling. A dynamic model for
milling process is built to determine relationship between SLE and cutting
parameters using full-discretization method (FDM). Monte-Carlo
simulation (MCS) method and artificial neural network (ANN) based MCS method
are proposed for predicting reliability of the milling process. Finally, a
numerical example is used to evaluate the accuracy and efficiency of the
proposed method.
2017-12-20T11:30:26+01:00https://doi.org/10.5194/ms-8-369-2017
<b>The design formulae for skew line gear wheel structures oriented to the additive manufacturing technology based on strength analysis</b><br>
Yueling Lyu, Yangzhi Chen, and Yifan Lin<br>
Mech. Sci., 8, 369-383, https://doi.org/10.5194/ms-8-369-2017, 2017<br>
In this paper, oriented to the additive manufacturing technology, a skew line gear pair, whose number of the line tooth of the driving line gear is 1, is designed to improve its strength and overall stiffness, to reduce its volume and manufacturing cost.This paper provides a basic theory for the skew line gear pair applied in conventional powered transmission field.
2017-12-14T11:30:26+01:00https://doi.org/10.5194/ms-8-359-2017
<b>A modified pseudo-rigid-body modeling approach for compliant mechanisms with fixed-guided beam flexures</b><br>
Pengbo Liu and Peng Yan<br>
Mech. Sci., 8, 359-368, https://doi.org/10.5194/ms-8-359-2017, 2017<br>
In the present paper, we investigate a modified pseudo-rigid-body (MPRB) modeling approach for compliant mechanisms with fixed-guided beam flexures by considering the load-dependent property. The proposed MPRB model provides a more analytical and accurate method to predict the performance characteristics such as deformation capability, stiffness variation, as well as error motions of complaint mechanisms and offers a new look into the design and optimization of beam-based compliant mechanisms.
2017-12-12T11:30:26+01:00https://doi.org/10.5194/ms-8-349-2017
<b>A novel 5-DOF high-precision compliant parallel mechanism for large-aperture grating tiling</b><br>
Zhongxi Shao, Shilei Wu, Jinguo Wu, and Hongya Fu<br>
Mech. Sci., 8, 349-358, https://doi.org/10.5194/ms-8-349-2017, 2017<br>
In combination with the advantages of parallel mechanisms and compliant
mechanisms, a 5-DOF compliant parallel mechanism is designed to meet the
requirements, such as large stroke, large load capacity, high precision and
high stability, for a large-aperture grating tiling device. The structure and
characteristics of the 5-DOF compliant parallel mechanism are presented. The
kinematics of the mechanism are derived based on a pseudo-rigid-body model as
well. To increase the tiling position retention stability of the mechanism, a
closed-loop control system with capacitive position sensors, which are
employed to provide feedback signals, is realized. A position and
orientation monitoring algorithm and a single neuron adaptive full closed-loop
control algorithm are proposed. Performance testing is implemented to verify
the accuracy and the tiling position retention stability of the grating
tiling device. The experimental results indicate that the tiling accuracy
reaches 0.2 µrad per step and 20 nm per step, and the tiling position retention
stability can achieve 1.2 µrad per 30 min and 35 nm per 30 min in the rotational
direction and the translational direction, respectively.
2017-11-30T11:30:26+01:00https://doi.org/10.5194/ms-8-337-2017
<b>A new methodology to identify minimum strain anatomical lines based on 3-D digital image correlation</b><br>
Jorge Barrios-Muriel, Francisco Javier Alonso Sánchez, David Rodríguez Salgado, and Francisco Romero-Sánchez<br>
Mech. Sci., 8, 337-347, https://doi.org/10.5194/ms-8-337-2017, 2017<br>
The design of these devices involves the human body as a support environment. Based on this premise, the development of wearable devices requires an improved understanding of the skin strain field of the body segment during human motion. This paper presents a new methodology to improve and optimize the design of wearable devices, specifically orthoses, based on the combination of biomechanical studies, computer aided design/computer aided engineering (CAD/CAE) tools and 3D printing technology.
2017-11-16T11:30:26+01:00https://doi.org/10.5194/ms-8-323-2017
<b>Toward force detection of a cable-driven micromanipulator for a surgical robot based on disturbance observer</b><br>
Wenjie Wang, Lingtao Yu, and Jing Yang<br>
Mech. Sci., 8, 323-335, https://doi.org/10.5194/ms-8-323-2017, 2017<br>
Force sensing plays an important role in minimally invasive surgery. In this study, a new asymmetric cable-driven type of micromanipulator for a surgical robot was designed, and a joint angle estimator(JAE) was designed based on the dynamical model system. Closed-loop control of the joint angle was carried out by regarding the JAE output as the feedback signal. An external force estimator was designed using a disturbance observer. The experimental results shown the correctness and validity.
2017-11-15T11:30:26+01:00https://doi.org/10.5194/ms-8-307-2017
<b>Design and evaluation of a new exoskeleton for gait rehabilitation</b><br>
Ionut Daniel Geonea and Daniela Tarnita<br>
Mech. Sci., 8, 307-321, https://doi.org/10.5194/ms-8-307-2017, 2017<br>
A new exoskeleton for human gait motion assistance and rehabilitation is proposed, to investigate motion capabilities and feasibility. Human gait analysis on healthy and disabled subjects is performed to obtain references motion laws for normal gait. A dynamic simulation model of exoskeleton is achieved in ADAMS computational environment. The exoskeleton prototype motion laws, resulted from motion analysis based on ultra speed video cameras are compared with human subject motion laws.
2017-10-17T11:30:26+02:00https://doi.org/10.5194/ms-8-299-2017
<b>Buckling of nonuniform carbon nanotubes under concentrated and distributed axial loads</b><br>
Mouafo Teifouet Armand Robinson and Sarp Adali<br>
Mech. Sci., 8, 299-305, https://doi.org/10.5194/ms-8-299-2017, 2017<br>
Buckling of nonuniform carbon nanotubes are studied under concentrated and distributed axial loads. Solution is obtained via weak formulation and Rayleigh-Ritz method for a combination of simply supported, clamped and free boundary conditions for uniformly and triangularly distributed axial loads. Buckling load under tip load is more sensitive to the change in the cross-section. However buckling load is more sensitive to the magnitude of the tip load for the clamped-free boundary conditions.
2017-10-09T11:30:26+02:00